The demand for coniferous trees, such as pines and firs, to make wood products continues to increase. One proposed solution to this problem is to identify individual trees that possess desirable characteristics, such as a rapid rate of growth, and produce numerous, genetically identical, clones of the superior trees by somatic cloning.
Somatic cloning is the process of creating genetically identical trees from tree tissue other than the male and female gametes. In one approach to somatic cloning, plant tissue is cultured in an initiation medium that includes hormones, such as auxins and/or cytokinins, to initiate formation of embryogenic cells, such as embryonal suspensor masses, that are capable of developing into somatic embryos. The embryogenic cells are then further cultured in a maintenance medium that promotes establishment and multiplication of the embryogenic cells. The multiplied embryogenic cells are then cultured in a development medium that promotes development of somatic embryos which can, for example, be placed within manufactured seeds and sown in the soil where they germinate to yield seedlings. The seedlings can be transplanted to a growth site for subsequent growth and eventual harvesting to yield lumber, or wood-derived products.
The present invention provides methods that are useful for somatic cloning of pine. In particular, the methods of the invention are applicable for the large-scale production of pine somatic embryos.